Expression of aromatase and synthesis of sex steroid hormones in skeletal muscle following exercise training in ovariectomized rats

Steroids ◽  
2019 ◽  
Vol 143 ◽  
pp. 91-96 ◽  
Author(s):  
Rengfei Shi ◽  
Xiangyang Tian ◽  
Yu Feng ◽  
Zepeng Cheng ◽  
Jianqiang Lu ◽  
...  
2018 ◽  
Vol 1 (3) ◽  
Author(s):  
Rengfei Shi ◽  
Xiangyang Tian ◽  
Quanguang Zhang ◽  
Zepeng Cheng ◽  
Yu Feng

Objective Age-related muscle wasting (sarcopenia) is accompanied by a decrease in estrogen levels which can compromise the health of aging women. Recent studies have shown that the key enzyme of estrogen synthesis (aromatase) is detected in the skeletal muscle. The purpose of this study was to investigate the effects of exercise on the expression of aromatase and the synthesis of sex steroid hormones in skeletal muscle following exercise training. Methods Fourteen female ovariectomized rats were divided into two groups, treadmill running (n=7) and sedentary (n=7) group. Exercise training on a treadmill (25 m/min, 60 min/day, 6 days/week) for 5 weeks. Immunofluorescence assay was used to detect estradiol and aromatase levels in soleus muscle and plantar muscle. Detected the expression of AKT, Aromatase, FoxO1, MyoD protein level by Western blotting. Results We found that in ovariectomized rats, exercise training significantly increased the soleus and plantar muscles mass. The level of aromatase expression and 17-b-estradiol (E2) were increased significantly in skeletal muscle following exercise training(P < 0.05). In addition, the down-stream Akt-FoxO1-MyoD signaling pathway was significantly regulated in both soleus and plantaris muscles following exercise(P< 0.05). Conclusions These results demonstrate that exercise training increased the expression of aromatase and local estrogen production in skeletal muscle, which potentially influences skeletal muscle in ovariectomized rats through activation of Akt-FoxO1-MyoD signaling pathway.


Life Sciences ◽  
2000 ◽  
Vol 66 (7) ◽  
pp. 641-648 ◽  
Author(s):  
Ayumi Sugaya ◽  
Takashi Sugiyama ◽  
Sachiko Yanase ◽  
Xiao-Xiong Shen ◽  
Hiroyuki Minoura ◽  
...  

2007 ◽  
Vol 292 (2) ◽  
pp. E577-E584 ◽  
Author(s):  
Katsuji Aizawa ◽  
Motoyuki Iemitsu ◽  
Seiji Maeda ◽  
Subrina Jesmin ◽  
Takeshi Otsuki ◽  
...  

The functional importance of sex steroid hormones (testosterone and estrogens), derived from extragonadal tissues, has recently gained significant appreciation. Circulating dehydroepiandrosterone (DHEA) is peripherally taken up and converted to testosterone by 3β-hydroxysteroid dehydrogenase (HSD) and 17β-HSD, and testosterone in turn is irreversibly converted to estrogens by aromatase cytochrome P-450 (P450arom). Although sex steroid hormones have been implicated in skeletal muscle regulation and adaptation, it is unclear whether skeletal muscles have a local steroidogenic enzymatic machinery capable of metabolizing circulating DHEA. Thus, here, we investigate whether the three key steroidogenic enzymes (3β-HSD, 17β-HSD, and P450arom) are present in the skeletal muscle and are capable of generating sex steroid hormones. Consistent with our hypothesis, the present study demonstrates mRNA and protein expression of these enzymes in the skeletal muscle cells of rats both in vivo and in culture (in vitro). Importantly, we also show an intracellular formation of testosterone and estradiol from DHEA or testosterone in cultured muscle cells in a dose-dependent manner. These findings are novel and important in that they provide the first evidence showing that skeletal muscles are capable of locally synthesizing sex steroid hormones from circulating DHEA or testosterone.


Aging Cell ◽  
2015 ◽  
Vol 14 (2) ◽  
pp. 236-248 ◽  
Author(s):  
Eija Pöllänen ◽  
Reeta Kangas ◽  
Mia Horttanainen ◽  
Paula Niskala ◽  
Jaakko Kaprio ◽  
...  

1995 ◽  
Vol 268 (1) ◽  
pp. G171-G176 ◽  
Author(s):  
T. S. Chen ◽  
M. L. Doong ◽  
F. Y. Chang ◽  
S. D. Lee ◽  
P. S. Wang

In vitro studies have shown that estrogen and progesterone can affect the contractile response and myoelectric activity of the gastrointestinal smooth muscle. The present study was designed to investigate the effect of sex steroid hormones on gastric emptying and gastrointestinal transit were assessed in rats 15 min after intragastric instillation of a test meal containing charcoal and 51Cr. Gastric emptying was determined by measuring the amount of labeled chromium contained in the small intestine as a percentage of the initial amount received. Gastrointestinal transit was evaluated by calculating both the geometric center of distribution of the radiolabeled marker and the charcoal transit in the intestine. The experimental animals included diestrus rats; ovariectomized rats treated with vehicle, estradiol, and/or progesterone; and normal male and orchiectomized rats treated with vehicle or testosterone. Female rats in diestrus had a slower gastric emptying and a lesser geometric center value than ovariectomized rats. Estradiol inhibited gastric emptying but did not affect gastrointestinal transit. Progesterone increased gastric emptying. Progesterone at lower dose (10 mg/kg) decreased the geometric center compared with higher doses (20 or 40 mg/kg) or vehicle controls. A mixture of estradiol (10 micrograms/kg) and progesterone (20 mg/kg) inhibited gastric emptying to a similar degree as estradiol (10 micrograms/kg) did. Testosterone had no influence on gastric emptying or gastrointestinal transit. These results suggest that estradiol and a mixture of estradiol and progesterone inhibit, whereas progesterone enhances, gastric emptying. Testosterone did not play a role in gastrointestinal motility.


2008 ◽  
Vol 104 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Katsuji Aizawa ◽  
Motoyuki Iemitsu ◽  
Takeshi Otsuki ◽  
Seiji Maeda ◽  
Takashi Miyauchi ◽  
...  

Sex steroid hormones, such as testosterone and estradiol, play important roles in developing both strength and mass of skeletal muscle. Recently, we demonstrated that skeletal muscle can synthesize sex steroid hormones. Whether there are sex differences in basal steroidogenesis or acute exercise-induced alterations of steroidogenesis in the skeletal muscle is unknown. We examined sex differences in the levels of testosterone, estradiol, and steroidogenesis-related enzymes, such as 17β-hydroxysteroid dehydrogenase (HSD), 3β-HSD, and aromatase cytochrome P-450 (P450arom), in the skeletal muscle at rest and after exercise. We studied the gastrocnemius muscles of resting rats (10 wk old) and exercised rats (10 wk old, treadmill running, 30 m/min, 30 min). Basal muscular testosterone levels were higher in males than females, whereas estradiol did not differ between sexes. Additionally, 17β-HSD, 3β-HSD, and P450arom transcript and protein expression were greater in females. After acute exercise, testosterone levels and 17β-HSD expression increased in muscle in both sexes. By comparison, muscular estradiol levels increased in males following exercise but were unchanged in females. Expression of P450arom, which regulates estrogen synthesis, increased after acute exercise in males but decreased after exercise in females. Thus a single bout of exercise can influence the steroidogenic system in skeletal muscle, and these alterations differ between sexes. The acute exercise-induced alteration of steroidogenic enzymes may enhance the local steroidogenesis in the skeletal muscle in both sexes.


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